As the Vikings prepare for Sunday’s game with Indianapolis at Lucas Oil Stadium, we asked Mike Chappell, the Colts beat writer for the Indianapolis Star, to give us his up-close-and-personal scouting report. Here are four things you need to know ...

1. Rookie quarterback Andrew Luck, as you’ve been hearing for the past 25 months now, is the real deal.

We only have one NFL regular season game to go on. But Luck was solid in the Colts’ opener at Chicago, completing 23 of 45 passes for 309 yards with a touchdown. Yes, he threw three interceptions and lost a fumble. And those mistakes will have to be reduced as soon as possible. But Luck’s overall command has been evident.

“I’ve said all along that he’s the least of my worries for this team this season,” Chappell said. “From everything we’ve seen, he’s been as advertised, maybe a little better. The game isn’t too big for him, the stage isn’t too big for him. He just has the disposition you want in your quarterback.”

Want specific examples of Luck’s poise? Chappell rewinds to the Colts’ second preseason game against Pittsburgh where Luck threw a pair of bad first half interceptions. He followed each with 80-yard touchdown marches.

On Sunday, after throwing his first interception against the Bears, Luck came back and led a 77-yard touchdown drive on the next series.

Plus on Luck’s final drive of the first half Sunday, he took over at his own 22 and quickly completed four straight passes for 59 yards in 27 seconds to put the Colts in field goal range.

Luck’s athleticism, Chappell said, is also underrated.

“We hear a lot about [Robert Griffin III] and Cam Newton and what they can do in the pocket. Luck’s not going to go out and run for 40 yards in a game. But he has incredible pocket presence. He has a knack for sliding away from pressure.”

2. The Vikings’ defensive line should be salivating at the battered offensive line it’s about to face.

Luck and running back Donald Brown might be in the most danger this season operating behind a line that doesn’t provide much security.

The Colts are particularly susceptible on the interior. Center Samson Satele is in his first year with the team. Starting left guard Joe Reitz is currently out with a knee injury and has been replaced by Seth Olsen, who at best is a mediocre back-up. At right guard, Mike McGlynn is also in his first year in Indianapolis. So is right tackle Winston Justice, who left Sunday’s game with a concussion and was relieved by Jeff Linkenbach, another subpar reserve.

“[Against Chicago], there were leaks everywhere, primarily up the middle,” Chappell said. “And if you ask any quarterback, they want protection up the middle so they can step up. Luck couldn’t step up, he stepped out.”

The line’s deficiencies are a worry for Brown, who had three runs of longer than 10 yards on his nine carries in Chicago. But he was also stopped for no gain or a loss on four runs.

3. The Colts have changed their defensive philosophy entirely but remain vulnerable in the secondary.

You thought the Vikings were atrocious defending the pass in 2011? Well, the Colts were the only team to allow opposing quarterbacks to complete a higher percentage of their throws (.712). Things certainly weren’t much better in Week 1 with Chicago’s Jay Cutler completing 21 of his 35 passes for 333 yards and two touchdowns. The Bears rolled up 428 yards of total offense, scored 41 points and had five players record receptions of longer than 20 yards.

The days of the Tampa 2 defense are history in Indy. And the new hybrid 3-4 defense installed by coach Chuck Pagano is much more aggressive – sometimes dangerously so.

“Now they’re pressing more and if the pass rush isn’t there, they’re going to give up 20 and 30 yard plays,” Chappell said. “That’s the tradeoff with this defense. They’re pressuring more and they’re putting their corners out there more.”

And the Colts’ depth at corner is worrisome. Jerraud Powers was solid in the opener. But Vontae Davis, who was acquired in a trade with Miami two weeks ago, struggled and may still need some time to adapt to the new system. Plus Justin King and Cassius Vaughn, the Colts’ third and fourth corners, just aren’t very good.

“The starters are OK,” Chappell said. “It’s the third and fourth corner who are going to get them beat.”

Making matters worse, premier pass rusher Dwight Freeney left the season opener in the first half with an ankle injury and may not be at full strength this week.

4. First-year coach Chuck Pagano has a different demeanor than his predecessors in Indianapolis and now faces a stretch that will test how good his first Colts team is.

Tony Dungy was known for his even-keeled leadership during his head coaching stint from 2002-08. Jim Caldwell followed for the next three seasons and was even more understated than Dungy.

“He’s very outgoing, very energetic,” Chappell said. “He’s been a breath of fresh air from a personality standpoint. Whether that works or not, we’ll see. He’s starting at a disadvantage because this roster is lacking so much.”

But just how quickly can Pagano get these Colts to make strides forward? Sunday’s lopsided loss in Chicago was expected. But the Colts next seven games set up nicely for a rebuilding team that needs to gain some confidence. The Vikings visit Sunday. And then Indianapolis will also have winnable homes games in Weeks 3, 7 and 9 against Jacksonville, Cleveland and Miami with a Week 8 trip to Tennessee mixed in.

“This is the stretch where we’ll know if this team can scrape out five or six wins this season,” Chappell said, “or if they’re going to be at the top of the draft again.”